html - Recursively outputting an ul-list with c# -

i'm trying output result table html ul-list. bind result list<>. in it's simpliest way can this. (i'm simulating binding important know sort columns in order)

list<link> linklist = new list<link>(); linklist.add(new link() { id = 1, parentid = null, title = "sport" }); linklist.add(new link() { id = 2, parentid = 1, title = "football" }); linklist.add(new link() { id = 3, parentid = 1, title = "handball" }); linklist.add(new link() { id = 4, parentid = 1, title = "golf" }); 

after call recursive method.

public htmlstring navigation { get; set; } navigation = createnavigation(linklist);  protected static htmlstring createnavigation1(list<link> linklist, string result = "", int? index = null) {     int maxindex = linklist.count() - 1;     if (!index.hasvalue)         index = maxindex;     else         index--;      link selectedlink;      if (index != 0)     {         selectedlink = linklist[index.value];          if (index != maxindex)         {             if (linklist[index.value + 1].parentid != selectedlink.parentid)             {                 return new htmlstring("<li id=\"" + selectedlink.id + "\">" + selectedlink.title + "<ul>" + createnavigation1(linklist, result, index) + "</ul></li>");             }             else             {                 return new htmlstring(createnavigation1(linklist, result, index) + "<li id=\"" + selectedlink.id + "\">" + selectedlink.title + "</li>");             }         }         else         {             return new htmlstring(createnavigation1(linklist, result, index) + "<li id=\"" + selectedlink.id + "\">" + selectedlink.title + "</li>");         }     }     else     {         selectedlink = linklist[index.value];         if (linklist[index.value + 1].parentid.hasvalue && linklist[index.value + 1].parentid.value == selectedlink.id)         {             return new htmlstring("<ul><li>" + selectedlink.title + "<ul>" + result + "</ul></li></ul>");         }         else         {             return new htmlstring("<ul><li>" + selectedlink.title + "</li>" + result + "</ul>");         }     } } 

when single step think runs should when @ output don't understand whats going wrong. result

<ul><li>sport<ul></ul></li></ul><li id="2">football</li><li id="3">handball</li><li id="4">golf</li> 

my wishing should this

<ul><li>sport<ul><li id="2">football</li><li id="3">handball</li><li id="4">golf</li></ul></li></ul> 

how come result appended after string , not inside it.

<ul><li>" + selectedlink.title + "</li>" + append here!(result) + "</ul>" 

where think incorrect?

thanks!

i didn't check wrong code check implementation instead.

public string gettree(list<link> linklist) {   var sb = new stringbuilder();   sb.append("<ul>");    foreach (var link in linklist) {     if (!link.parentid.hasvalue) {       sb.append("<li>");       sb.append(link.title);       sb.append(getchildren(linklist, link.id));       sb.append("</li>");     }   }    sb.append("</ul>");   return sb.tostring(); }  private string getchildren(list<link> linklist, int parentid) {   var sb = new stringbuilder();    var childlist = m in linklist                   m.parentid == parentid                   orderby m.id                   select m;    if (childlist.count() > 0) {     sb.append("<ul>");     foreach (var link in childlist) {       sb.append("<li>");       sb.append(link.title);       sb.append(getchildren(linklist, link.id));       sb.append("</li>");     }     sb.append("</ul>");   }   return sb.tostring(); }  navigation = new htmlstring(gettree(linklist));